Protective boots used on automobile components such as a boot for a constant velocity joint (CVJ), perform several functions including protecting the joint from outside dirt and debris, as well as maintaining lubricant around the joint. Many protective boots, however, must attach to automotive components which do not have a cylindrical external configuration to which the boot may be clamped. For example, due to the bearing configuration of typical constant velocity joints, the shaft to which one end of the CVJ boot must clamp is lobed, rather than cylindrical. Thus, in order to perform its protective functions properly, a CVJ boot requires a seal or bushing element at one end to be clamped between the boot and the shaft. The bushing may have a tri-lobed internal configuration for cooperation with the joint element.
In use, however, the addition of this extra element increases the ways in which the protective boot may fail. For example, if there is an incomplete seal between the bushing and the boot, lubricant may be allowed to escape from the joint or contaminants allowed to enter.
Accordingly, there is a need for a boot and bushing assembly which provides a suitable external clamping surface and an internal irregular surface which can be configured to meet the requirements of a mechanical structure in association with which the product is to be used. Producing such a product is very difficult using a single molding technique. Thus, it may be desirable to produce the boot with its typical bellows section in a blow molding process. Similarly the bushing with its required internally projecting lobes may best be produced using other techniques such as injection molding. When there is a separate bushing to be used with a separate boot there remains the question of sealing the bushing to the boot. Normally this is accomplished by means of an encircling clamp typically referred to as a hose clamp which clamps the boot against the bushing and the bushing against the underlying mechanical component. This, in turn, means that there are at least three separate items that must be stocked to the automotive assembly plant including a separate boot, a separate bushing, and the encircling clamp.
Accordingly, it would be desirable to produce an assembly of a boot and bushing for shipment to and use at an automotive assembly plant. Such a product would require that the bushing be maintained within the boot prior to attachment to the mechanical component. In addition, such a component would require adequate sealing between the bushing and the boot to ensure that lubricants in the boot would not escape when the boot is in use with an automobile or similar structure.